A promising scheme for scalable trapped-ion quantum simulators and processors rely on assembling a larger system from smaller modules between which quantum information is exchanged.
This exchange can be realized by physical transport of the ions as carriers of quantum information between those modules.
The transport operations have to be performed with high-fidelity to meet the requirements of efficient error correction that is needed for scalability.
We report for the first time physical transport of quantum information encoded into trapped ion qubits with a fidelity 99.9994%, that is, well above a commonly accepted error correction threshold.
In our experiment we embedded ion transport into Ramsey measurements and compared the results for different numbers of transport operations. During the measurements a single Ytterbium ion was transported up to 4000 times over a distance of 280 micrometer in a microstructured ion trap.